Talk:Dimensionless physical constant

Fine-structure constant
There is a problem with this page in that it seems to assert that the electromagnetic coupling constant and the fine structure constant are different things. The weak nuclear coupling constant is also omitted.


 * I fixed this stuff and gave a more detailed listing of the 25 constants in the current-day Standard Model. John Baez 23:55, 21 September 2006 (UTC)
 * thanks, John. we really can use some real experts on articles like this.  r b-j 00:29, 22 September 2006 (UTC)

Does anyone else think that something be added to clarify that "constants" like the fine structure constant depend on the energy at which they are measured. For example,

$$\alpha(92\ \mathrm{GeV}) \approx 1/127$$

while, $$\alpha(0\ \mathrm{GeV}) \approx 1/137$$ Zekemurdock 18:08, 31 October 2006 (UTC)


 * i think the fundamental physical constant called the "fine-structure constant" and listed as this universal constant in listed is meant to be the one at 0 energy. but this issue of physics should be in the Fine-structure constant article.   is there either a derived or empirical equation that maps $$ \alpha \ $$ from energy? r b-j 18:32, 31 October 2006 (UTC)

Martin Rees's Six Numbers
The section 'Martin Rees' 6 numbers' does not fit in with the rest of the article. It definitely does not deserve a section on its own with equal weight to 'The standard model' section. We are talking about a book where "Rees mulls over the following six numbers, which he considers fundamental to present-day physical theory". That would be acceptable if it was published in a scientific journal, otherwise the whole article could as well be cluttered with what an army of scientific writers consider fundamental to present-day physics. Put it another way, when I first read the article and checked the contents I thought "uhm, Martin's 6 numbers...I've never heard of those, they must be a kick ass scientific breakthrough on the field..." and it ended up being not much more than publicity (however good the book probably is). —Preceding unsigned comment added by 88.26.70.195 (talk) 14:21, 26 December 2008 (UTC)
 * I agree that the section should not be on equal standing with 'The standard model' section, so I have moved it to be a subsection of 'Other'. It tends to overwhelm the other three entries (with only a couple of sentences each) but the material should be kept.  One possibility would be to create a Just Six Numbers article and shorten the entry here to single paragraph. -- Thinking of England (talk) 03:54, 23 August 2009 (UTC)

Planck's constant displays as a square in Google Chrome
When I view this article with Mozilla Firefox or Internet Explorer, the h with a slash through it (Planck's reduced constant) displays correctly. When I view it with Google Chrome, however, it shows up as a square or empty box. Oddly, even on Google Chrome, when I click "edit" to see the wiki-code, the symbol appears correct there. I thought I would mention this to see if anyone else knows how to correct this in the article itself, so that it will work in all browsers; or if it is just a browser bug and I need to live with it. Thanks in advance! CosineKitty (talk) 04:18, 14 February 2010 (UTC)


 * It's just whether the character is included in each of the various fonts that your browser uses (a proportional font is generally used in display of ordinary HTML text, while a non-proportional font is used in display of form entry box text, so it's not all that surprising that some characters might be in one of the fonts, but not the other.) AnonMoos (talk) 05:03, 14 February 2010 (UTC)


 * "If Ω>1, the universe will experience a Big Crunch. If Ω<1, the universe will expand forever". This is just wrong.  It is true if the cosmological constant is zero or if the universe is flat (the universe is flat if Ω and the cosmological constant add up to zero).  Since just after this a non-zero cosmological constant is discussed, we have to assume that Rees isn't limiting himself to either of these special cases.  For general values of lambda (the cosmological constant) and Ω, one can calculate whether the universe will expand forever or not, but it is not that simple.  This needs to be fixed.  — Preceding unsigned comment added by 193.29.76.37 (talk) 20:19, 23 January 2012 (UTC)

Masses of quarks and leptons..
I was just reading the Baez reference where 26 dimensionless fundamental constants are enumerated. He identifies the 12 particle masses "divided by the Planck mass" as fundamental. He doesn't mention relative to another natural unit of mass.

You could have all of the remaining 11 masses expressed relative to the electron mass and then have the electron mass in terms of the Planck mass, which is the sqrt of the gravitational coupling constant, αG. So it's still 12 numbers, either the particle mass ratios against a specific particle along with αG or it's all of the particle masses against the Planck mass. Rather than explain this in the article, I think it would be simpler to just say relative to the Planck mass and leave it. Then the gravitational coupling constant need not enter into it. If you don't like, you can fix it. 70.109.180.126 (talk) 04:22, 20 March 2010 (UTC)

Variation of physical constants
Regarding:


 * The question whether the fundamental dimensionless constants depend on space and time is being extensively researched. Despite several claims, no confirmed variation of the constants has been detected.

A simple Google scholar search reveals plenty of papers that should serve to provide a citation that physical-constant-variation is being "extensively studied":

http://scholar.google.co.uk/scholar?q=variation+of+fundamental+constants&hl=en&as_sdt=0&as_vis=1&oi=scholart

.===.
 * The values of the dimensionless fundamental physical constants cannot be calculated; they are determined only by physical measurement. This is one of the unsolved problems of physics.

 I posit that these (perhaps 26+) values are parameters for the existence of our universe.  If all that is not prohibited by the laws of physics will occur (ie: virtual particle (Hawking) radiation, etc.), then presuming that the big bang (like other phenomena) was not unique, then some aspect(s) of its nucleation corresponds to those values (and might even affect interactions between those big-bang products (‘verses’)). This concept can be visualized as a multi-dimensional Cartesian meta-space, in which each constant, being a dimensional axis, allows you to catalog each verse by positioning its index along those dimensions according to the ‘value’ of its constants.  Since variations in these values can determine the viability, longevity, livability, etc. of the result, there might be a constellation or envelope of related verses that would be stable enough to interact with each other in subtle or profound ways, and it might be possible to predict what ‘neighboring’ verses might influence ours in ways not yet explored. (I doubt I am the first to consider this avenue of meta-ploration. See also "Plenivers" v "Multiverse" & near-by considerations:A near-by consideration is http://www.newscientist.com/article/dn26267-four-ways-you-can-see-the-multiverse.html) JRB 141027 --Wikidity (talk) 23:18, 27 October 2014 (UTC)

"c" as a fundamental dimensionless constant
In relativity, space and time are the same type of dimension as exemplified in Einstein's "Relativity" Appendix 2 where meters=i*c*seconds. This is seen again in the SI definitions of meter and second. So "c" is dimensionless. The problem is that in order to incorporate this into plank units (to remove either length or time), a square root of -1 would need to be carried along as the distinguishing factor between length and time. This has the advantage of describing mass as the negative of energy instead of being considered "equal" or using different plank units for mass, energy, and momentum (the i carries into momentum which makes it a vector quantity). Plank voltage reduces to Mass/Charge, taking out a time and length.Ywaz (talk) 17:14, 25 September 2011 (UTC)
 * I know you think that, Ywaz, but you're mistaken. Both semantically and substantively.  70.109.185.68 (talk) 02:35, 26 September 2011 (UTC)
 * No, I don't know that, so you're mistaken, as well as using a personal attack as a form of argument. "c" should disappear in Plank units as it does, but the "i" conversion factor needs to be carried with it and thereby allowing the removal of either space or time from equations and constants. Ywaz (talk) 13:50, 1 July 2012 (UTC)

Problem with dimensionless constants.
A constant is not a dimesionless constant unless it would be able to be measured up to any accuracy no matter how high provided that a sufficent amount of time is devoted to determining it to that accuracy. There's no reason to endlessly search for a mathematical constant that happens to match a dimesionless constant if it turns out that that constant is not an exact number that can be measured with arbitrarily high accuracy. For instance, I don't think the fine structure constant is an exact number. The fine structure constant determines what fraction of the speed of light an electron orbiting around a proton in its 1st energy level will have and its actual speed will be approximately that speed divided by the number of its energy shell and its radius appoximately the radius of its 1st shell times the square of its shell number. That formula is only approximate due to the finititude of the speed of light. The further away the electron is from the proton, the more accurately the fine structure constant can be determined, but the problem is that it can't be determined with arbitraily high accuracy because the cosmological constant prevents you from taking the proton and electron too far away from each other and doing an experiment on them.

This article has another problem of calling 3 a dimesionless physical constant because it not only is the number of observable dimensions but can also be mathematically defined. Also keep in mind that 2π is not a dimesionless physical constant either even though it's the ratio between angular frequency and frequency for a spinning top because it can be determined mathematically. Blackbombchu (talk) 02:52, 17 June 2013 (UTC)


 * I'm not sure I follow you: are you saying these numbers are not constants, or not dimensionless? If the former, how can 3 or 2π not be constant, without redefining pretty much the whole of math? If the latter, what ARE their dimensions? ComaVN (talk) 08:58, 10 October 2013 (UTC)

Weinberg angle
How is the Weinberg angle captured in these constants? I'm curious, because I see the CKM matrices are included directly, and I expected the Weinberg angle to be captured directly as well. I suspect it is here, but implicit as some kind of mass ratio, or something. Anyone know? 70.247.160.87 (talk) 00:27, 31 March 2013 (UTC)

I was not in favor of changing the name of the article and the lastest revert is the reason.
This name changed happened back then: 70.109.179.96 (talk) 06:30, 8 January 2014 (UTC)

A formula for G?
The grandiose claim "Of all fundamental constants, only formulae for value of the Newtonian gravitational constant G have been given" has been given, and now the IP is insisting on it (with the edit summary relative to the rest of the article (also not discussed in talk) this was the well made part). I don't even see the claim as being substantiated in the arXiv paper cited. Some others please take a look. The same is the case at Gravitational constant with this revert. —Quondum 17:25, 15 March 2015 (UTC)
 * I don't think it's "grandiose" - because it came about in reaction to what the article was saying previously: "There are no known..." Inorout (talk) 19:14, 23 March 2015 (UTC)


 * Q, we both know you're absolutely correct. (I'm not the same IP.)  $$G$$ is not a dimensionless physical constant and can take on whatever real, positive, and finite value we choose with a corresponding definition of units.  I do cringe a little with some of your prolific WP edits, but am too lazy for the most part to take them on (since I haven't seen any yet that are egregiously wrong).  But this other IP is goofy. 166.184.170.35 (talk) 20:13, 15 March 2015 (UTC)
 * Just relax. This'll no doubt be cleared up soon enough; not need to get it "right" immediately.  What you mean my the cringeworthiness of some of my edits is unclear: perhaps you could be a bit more specific on my talk page; I'm not averse to constructive criticism. —Quondum 00:36, 16 March 2015 (UTC)
 * I agree with Quondum, Inorout's material doesn't belong in the article. It is only supported by a single unpublished paper which is, to put it politely, at variance with established physics such as the General Theory of Relativity.   The source is a WP:PRIMARY SOURCE; WP requires primary sources which establish new facts to be backed up by secondary sources (PSTS), "Exceptional claims require exceptional sources".  Also, Inorout's assertion that the Omerbashich result is the only derivation of a physical constant needs sourcing, otherwise it is SYNTH. -- Chetvorno TALK 16:32, 23 March 2015 (UTC)
 * There are 1000s of unpublished arxiv papers used as references in Wikipedia. Who is to say which ones are OK and which aren't? You? Also, how is the new reference "at variance with established physics such as the General Theory of Relativity"? Is it your OR, or do you have another reference that says so? Inorout (talk) 19:14, 23 March 2015 (UTC)


 * Inorout, I don't understand your insistence that this single unconfirmed, unpublished paper be included in WP. Rather than just reverting, could you discuss it on this Talk page?   I'd like to hear your case for this material.  Maybe we can work out a compromise. -- Chetvorno TALK 16:44, 23 March 2015 (UTC)

Interesting discussion. Some 2 numbers, both coming from valid references afawk, were compared. Then the comparison was abruptly removed without discussion required for substantial edits such as removal of good-faith text and new references. It would be great if some of you would keep your personal opinion about (any) science references to yourselves. Those opinions are irrelevant, not to mention they constitute OR. Inorout (talk) 19:12, 23 March 2015 (UTC)


 * FYI, User:Inorout has been indefinitely blocked as a suspected sockpuppet of User:Bosnipedian, (Bosnipedian sockpuppet archive) who was also a promoter of the work of Mensur Omerbashich.  The IPs which supported him were also socks.  Apparently this guy pops up new socks every month  which promote the works of Omerbashich.  Heads up. -- Chetvorno TALK 21:17, 23 March 2015 (UTC)


 * Inorout? Looks like out. Seriously, the term "scientific reference" refers to material published in peer-reviewed scientific journals. The contested "paper" is a good laugh - but that doesn't warrant mention in the article (though it could use a bit of humor). YohanN7 (talk) 11:48, 24 March 2015 (UTC)

Higgs boson mass now measured and not tentative
(I tried to follow the instructions for requesting edits in protected pages; apologies if I am not doing this right)

The best mass measurement to date is 125.09±0.24 GeV, cf. Eq. (3) in http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.114.191803

More things I noticed: The Baez link is quoted as 2002, but following the link there is a 2011 version.

Finally, Baez explicitly writes "If this new extension of the Standard Model holds up, and all the neutrinos have nonzero mass, this brings the total of fundamental constants to 25!", which leads to what I knew was the answer for SM parameters: 21. The text should be changed to reflect that the "vanilla" SM has no neutrinos in it and 21 parameters.

— Preceding unsigned comment added by Adavidtm (talk • contribs) 08:44, 6 September 2015 (UTC)
 * Red information icon with gradient background.svg Not done: Please provide an "please change X to Y format" with reliable sources to each one. Make sure that you're making it clear what exactly you want changed with evidence to support it. JustBerry (talk) 00:18, 8 September 2015 (UTC)
 * Or Be bold... actually I changed those two things earlier than your comment here. --mfb (talk) 18:45, 8 September 2015 (UTC)

First Sentence
"In physics, a dimensionless physical constant, [...], is a physical constant that is dimensionless."

Rule number one of a definition is that you don't use the word you're trying to define to define it. "A dictionary is a book that is a dictionary."


 * It used to be that the official title of this page was "Fundamental physical constant", and I would support changing the title back to that (rather than the redirect). Problem is the definition fits with physical constant and dimensionless wikilinked to their specific definitions. 98.118.36.105 (talk) 19:58, 4 April 2016 (UTC)

Relation to physical constant article
This article makes a big deal out of the difference between dimensionless and dimensional. But then it ends up just discussing physical constants in general.

The rest masses of fundamental particles are dimensional physical constants. But of course you can call them "dimensionless" if you look at ratios between them, or between them and the Planck mass. The interesting thing here is not whether you express them in the Planck mass or in kg, the interesting thing is that they cannot be derived from more fundamental principles. So I have to say the entire "dimensionless" focus strikes me as a bit of a red herring.

The "1/137" thing is intriguing, and has traditionally been used as a starting point to philosophize about the mathematical universe, but apart from this, the article essentially duplicates the scope of physical constant, just with a peculiar focus on looking at ratios.

I am doubtful that "physicists increasingly" focus on the "dimensionless" aspects (as the article asserts kind of from thin air). Physicists are nothing if not pragmatic. They simply do not care about choice of units. The electron mass is the electron mass, and equally "fundamental" regardless of the units used. --dab (𒁳) 07:40, 12 May 2016 (UTC)


 * after looking into this in some detail, I would rephrase my merge request to the effect that the "physical constant" article is already about "dimensionless physical constants", where "dimensionless" means "measured as the ratio of other fundamental constants, e.g. in any system of natural units". This should by all means be made crystal clear, because the possibilities for confusion are grave, but it should be made crystal clear on a single page. The current situation is a result of such confusion, and adds to it, because it appears to imply that there are "dimensional physical constants" in any meaningful sense. --dab (𒁳) 14:18, 12 May 2016 (UTC)

Possibly non-noteworthy article; propose removal.
recently added citations to an article he wrote:, ,  This does not appear to me to be noteworthy, and I suggest that it be removed. Isambard Kingdom (talk) 18:30, 16 November 2016 (UTC)

The server for ref 2 is in process of update and not currently working. Waiting for an operational date.2602:304:B10B:A640:2C0C:A9BB:A38C:29CD (talk) 21:44, 16 November 2016 (UTC)
 * 1) the server is now operational for ref 2. Jim Johnson 11:40, 17 November 2016 (UTC)  — Preceding unsigned comment added by Jimjohnson2222 (talk • contribs)


 * I support removing it also as reference and the associated content. The abbreviations "SMPP" and "SMC" are very uncommon.
 * The parameters "baryons mass per photon, cold dark matter mass per photon, and neutrino mass per photon" are not fundamental constants in physical laws: no physical process with the same initial conditions would be different if those parameters would have different values. They are dimensionless and used as constants in physics, however, so we have some conflict about scope here. --mfb (talk) 17:37, 18 November 2016 (UTC)

The cosmological constants are input to equations for cosmological evolution. In the article “Dimensionless constants, cosmology, and other dark matters” (Tegmark, Aguirre, Rees, and Wilczek), they are listed as “dimensionless” input parameters. A sentence could be added to clarify this but the reference to Tegmark’s book is important (the book references the article).Jim Johnson 21:00, 18 November 2016 (UTC) — Preceding unsigned comment added by Jimjohnson2222 (talk • contribs)
 * 1) The terms SMPP and SMC are used frequently but not universal. Brian Greene in his books uses Standard Model of particle physics and Max Tegmark uses cosmological standard model. However, since the terms are not used in Wikipedia, it should say Standard Model and Cosmological Model.
 * "The cosmological constants are input to equations for cosmological evolution." - sure. And the mass of Earth is an input to equations for satellite orbits, and the size of particle detectors is an input in experimental particle physics, you can make both dimensionless if you want. That doesn't make them fundamental constants of physics. As I said, the cosmology constants in the article are dimensionless, but not fundamental, and the article tries to combine both. --mfb (talk) 19:42, 19 November 2016 (UTC)

✅ Per what seems to be some reasonable support, I've removed the citation to an paper that Jim Johnson wrote and which he, himself, was repeatedly inserting into this Wiki article. Isambard Kingdom (talk) 23:14, 19 November 2016 (UTC) 2602:304:B10B:A640:40A9:7E78:F78E:8DA2 (talk) 00:41, 20 November 2016 (UTC)
 * 1) I think Isambard has missed the reviewers point – he was arguing for deletion of the Tegmark reference. It should be change back.
 * Really? Tegmark is one of the world's most famous scientists writing on the multiverse. Isambard Kingdom (talk) 00:47, 20 November 2016 (UTC)


 * 1) Isambard, as you may not recall, it was my edit that added both mine and Tegmark references. If you read what you call “support” it says: “The cosmological constants are input to equations for cosmological evolution." - sure. And the mass of Earth is an input to equations for satellite orbits, and the size of particle detectors is an input in experimental particle physics, you can make both dimensionless if you want. That doesn't make them fundamental constants of physics”. His minor point was the SMPP terminology which I addressed. Now what is your logic?  2602:304:B10B:A640:40A9:7E78:F78E:8DA2 (talk) 01:18, 20 November 2016 (UTC)
 * We can remove all of the material in that section. Is that what you are suggesting? Otherwise, it is not appropriate for you to cite your own work in this article. You are not a notable expert on the subject and your work is published in obscure places and has never been cited by anybody that I can see. Thank you. Isambard Kingdom (talk) 01:21, 20 November 2016 (UTC)


 * No, I am not suggesting to remove all or any of what I submitted. I previously responded to the question on the Tegmark reference from Mfb with an explanation on why it should remain and said a sentence could be added to clarify. I also said the SMPP/SMC mnemonics could be removed as Mfb recommended. I will soon make these corrections. I am checking on the citing’s and downloads of my articles. Thanks for your interest.Jim Johnson 00:53, 21 November 2016 (UTC) — Preceding unsigned comment added by Jimjohnson2222 (talk • contribs)
 * Jim, you should consult with, since he/she has already edited that part of the article and, per above, does not seem to support citing your article. I will, however, let him/her speak for himself/herself. Thank you. Isambard Kingdom (talk) 01:51, 21 November 2016 (UTC)

Clarification to cosmology constants and related reference changes
I recommend the following changes. 1. Add below to the Cosmology Constants section. This is an important distinction concerning the cosmology model. The reference provides clarifying detail. "The cosmology dimensionless constants are independent from, and cannot be derived from, the Standard Model dimensionless constants." [add to References, Scott, Douglas, 2006. The Standard Cosmological Model. Canadian J. Physics, 84: 419-435. DOI: 10.1139/p06-066, pp 12-12] 2. Delete from External Articles the Kaku book. I did not find any information in the book on dimensionless constants. 3. Add to External Articles a source covering dimensionless constants from particle physics and cosmology:  Johnson, James, R., 2015. Discovering Nature's Hidden Relationships, an Unattainable Goal?" Physics International 6 (1): DOI: 10.3844/pisp.2015.3.10. http://thescipub.com/PDF/pisp.2015.3.10.pdf Please advise on changes. If approved, I will put in proper format and make changes. Jim Johnson 17:31, 22 July 2017 (UTC)  — Preceding unsigned comment added by Jimjohnson2222 (talk • contribs)

The recent reverts
, 50.47.109.91: Stop this edit war, please find some agreement here. I prefer the longer version (from the IP) but don't have a strong opinion on the topic. --mfb (talk) 11:41, 31 May 2019 (UTC)
 * The "longer version" is the pre-existing status quo with a small amount of explicit amplification that I did to try to deal with virus's first-stated concern (about redundancy). I am willing to go back to exactly the prior status quo, but I thought that the changes I made sufficed in correcting any simple semantic redundancy.  Expanding on a concept to explain it is not a simple semantic redundancy.  It's explaining.  Part of the purpose of an encyclopedia is to explain concepts relevant to the primary topic of the article.  50.47.109.91 (talk) 08:24, 2 June 2019 (UTC)
 * Status quo is not by definition superior and I'm surprised it is even used as an argument. As I mentioned in one of my edits, I can't imagine that there exists a person who after seeing the phrase "dimensionless physical constant" wonders whether it means a constant that is dimensionless or not, and only after reading the sentence "is a physical constant that is dimensionless" realises what it actually means. If and 50.47.109.91 genuinely think that this redundancy helpful to anyone, there is a lot of work to be done on multiple Wikipedia articles such as Electromagnetic field (a field that is electromagnetic), Fundamental interaction (an interaction that is fundamental) etc.. Independovirus (talk) 09:00, 3 June 2019 (UTC)
 * Oh come on... I'm sure you can find real arguments instead of just being silly. --mfb (talk) 00:26, 4 June 2019 (UTC)
 * Of course,, you just provided that argument yourself. If you think that my last message was silly, defining "dimensionless physical constant" as "physical constant that is dimensionless" - is silly. Before this edit section, I had a discussion with the user who kept reverting my changes, where I provided the same argument from a semantic standpoint: it's redundant. The user kept saying that it is "to make it absolutely clear", but I honestly don't see how repeating the same phrase in a different grammatical structure makes it any clearer or adds any value. As I said above, I can't imagine there is a person who after reading "a physical constant that is dimensionless" will be any more illuminated about what "dimensionless physical constant" is. I am, however, aware that I am sometimes wrong about these things, so I was wondering about your experience of this opening statement. What did you, , learn from the phrase "a physical constant that is dimensionless" that you didn't know after reading the phrase "dimensionless physical constant"? Independovirus (talk) 15:39, 5 September 2019 (UTC)
 * I'm a physicist, I'm not the target audience of this article. One advantage is the natural link to Dimensionless quantity, for example, so people who use the article to learn something new can learn more about how dimensions matter. You also remove the "pure number". --mfb (talk) 01:42, 6 September 2019 (UTC)